igb: cleanup tx dma so map & unmap use matching calls

The igb driver was using map_single to map the skbs and then unmap_page to
unmap them.  This update changes that so instead uses skb_dma_map and
skb_dma_unmap.

In addition the next_to_watch member of the buffer_info struct was being
set uneccesarily.  I removed the spots where it was set without being needed.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 35 insertions, 31 deletions

diff --git a/drivers/net/igb/igb_main.c b/drivers/net/igb/igb_main.c
index d6dda1621166..ca842163dce4 100644
--- a/drivers/net/igb/igb_main.c
+++ b/drivers/net/igb/igb_main.c
@@ -2257,19 +2257,14 @@ static void igb_free_all_tx_resources(struct igb_adapter *adapter)
 static void igb_unmap_and_free_tx_resource(struct igb_adapter *adapter,
                                            struct igb_buffer *buffer_info)
 {
-        if (buffer_info->dma) {
-                pci_unmap_page(adapter->pdev,
-                                buffer_info->dma,
-                                buffer_info->length,
-                                PCI_DMA_TODEVICE);
-                buffer_info->dma = 0;
-        }
+        buffer_info->dma = 0;
         if (buffer_info->skb) {
+                skb_dma_unmap(&adapter->pdev->dev, buffer_info->skb,
+                              DMA_TO_DEVICE);
                 dev_kfree_skb_any(buffer_info->skb);
                 buffer_info->skb = NULL;
         }
         buffer_info->time_stamp = 0;
-        buffer_info->next_to_watch = 0;
         /* buffer_info must be completely set up in the transmit path */
 }
 
@@ -3078,25 +3073,33 @@ static inline int igb_tx_map_adv(struct igb_adapter *adapter,
         unsigned int len = skb_headlen(skb);
         unsigned int count = 0, i;
         unsigned int f;
+        dma_addr_t *map;
 
         i = tx_ring->next_to_use;
 
+        if (skb_dma_map(&adapter->pdev->dev, skb, DMA_TO_DEVICE)) {
+                dev_err(&adapter->pdev->dev, "TX DMA map failed\n");
+                return 0;
+        }
+
+        map = skb_shinfo(skb)->dma_maps;
+
         buffer_info = &tx_ring->buffer_info[i];
         BUG_ON(len >= IGB_MAX_DATA_PER_TXD);
         buffer_info->length = len;
         /* set time_stamp *before* dma to help avoid a possible race */
         buffer_info->time_stamp = jiffies;
         buffer_info->next_to_watch = i;
-        buffer_info->dma = pci_map_single(adapter->pdev, skb->data, len,
-                                          PCI_DMA_TODEVICE);
+        buffer_info->dma = map[count];
         count++;
-        i++;
-        if (i == tx_ring->count)
-                i = 0;
 
         for (f = 0; f < skb_shinfo(skb)->nr_frags; f++) {
                 struct skb_frag_struct *frag;
 
+                i++;
+                if (i == tx_ring->count)
+                        i = 0;
+
                 frag = &skb_shinfo(skb)->frags[f];
                 len = frag->size;
 
@@ -3105,19 +3108,10 @@ static inline int igb_tx_map_adv(struct igb_adapter *adapter,
                 buffer_info->length = len;
                 buffer_info->time_stamp = jiffies;
                 buffer_info->next_to_watch = i;
-                buffer_info->dma = pci_map_page(adapter->pdev,
-                                                frag->page,
-                                                frag->page_offset,
-                                                len,
-                                                PCI_DMA_TODEVICE);
-
+                buffer_info->dma = map[count];
                 count++;
-                i++;
-                if (i == tx_ring->count)
-                        i = 0;
         }
 
-        i = ((i == 0) ? tx_ring->count - 1 : i - 1);
         tx_ring->buffer_info[i].skb = skb;
         tx_ring->buffer_info[first].next_to_watch = i;
 
@@ -3230,6 +3224,7 @@ static int igb_xmit_frame_ring_adv(struct sk_buff *skb,
         unsigned int first;
         unsigned int tx_flags = 0;
         u8 hdr_len = 0;
+        int count = 0;
         int tso = 0;
         union skb_shared_tx *shtx;
 
@@ -3291,14 +3286,23 @@ static int igb_xmit_frame_ring_adv(struct sk_buff *skb,
                  (skb->ip_summed == CHECKSUM_PARTIAL))
                 tx_flags |= IGB_TX_FLAGS_CSUM;
 
-        igb_tx_queue_adv(adapter, tx_ring, tx_flags,
-                         igb_tx_map_adv(adapter, tx_ring, skb, first),
-                         skb->len, hdr_len);
-
-        netdev->trans_start = jiffies;
-
-        /* Make sure there is space in the ring for the next send. */
-        igb_maybe_stop_tx(netdev, tx_ring, MAX_SKB_FRAGS + 4);
+        /*
+         * count reflects descriptors mapped, if 0 then mapping error
+         * has occured and we need to rewind the descriptor queue
+         */
+        count = igb_tx_map_adv(adapter, tx_ring, skb, first);
+
+        if (count) {
+                igb_tx_queue_adv(adapter, tx_ring, tx_flags, count,
+                                 skb->len, hdr_len);
+                netdev->trans_start = jiffies;
+                /* Make sure there is space in the ring for the next send. */
+                igb_maybe_stop_tx(netdev, tx_ring, MAX_SKB_FRAGS + 4);
+        } else {
+                dev_kfree_skb_any(skb);
+                tx_ring->buffer_info[first].time_stamp = 0;
+                tx_ring->next_to_use = first;
+        }
 
         return NETDEV_TX_OK;
 }